Advice on how to stop a Single slipping?

[Edwardian]

.... a model, not the prototype.

 

I have a single, she's willing enough, but slips all over the place.  It might even be that the gears are not meshing.  I have yet to take her apart. 

 

Also, she makes a noise like a tortured cat (which I've never heard), or a child learning the violin (which I have).

 

So, actions on slipping, screaming single?

[Florence Locomotive Works]

Honorable Mayor, 

 

 

How strange it is to see yourself out of the hall posing such questions!

 

Having never owned a single, my advice may not be the best. But I would first test it off the track, and see how true there wheels are, and if the child-violin-tortured-cat symphony returns. If all seems well, place it in the track without the body on, and stick some lead weights on it with blue tack. If the results are better, then more weight is probably needed. If they are the same, then I’m not sure what to do.

 

Out of curiosity, what engine is it?

 

Douglas

[Miss Prism]

[Edwardian]

3 minutes ago, Miss Prism said:

 

Yep, precisely why I specified model, not prototype because I knew, I just knew, someone would mention sand!! 

 

5 minutes ago, Florence Locomotive Works said:

Out of curiosity, what engine is it?

 

 

 

One of the greatest of them all ....

 

 

 

BTW, it's white metal, so pretty heavy to begin with. I suspect the power is there, it's just not doing what it should.

 

[Florence Locomotive Works]

4 minutes ago, Edwardian said:

 

Yep, precisely why I specified model, not prototype because I knew, I just knew, someone would mention sand!! 

 

 

One of the greatest of them all ....

 

 

 

BTW, it's white metal, so pretty heavy to begin with. I suspect the power is there, it's just not doing what it should.

 

Is it the old K’s one with K’s motor? If so then weight isn’t the problem, it will almost certainly be the motor. 

[J. S. Bach]

34 minutes ago, Edwardian said:

 ...snip... Also, she makes a noise like a tortured cat (which I've never heard), ...snip...

You have heard bagpipes, haven't you?

[Edwardian]

14 minutes ago, Florence Locomotive Works said:

Is it the old K’s one with K’s motor? If so then weight isn’t the problem, it will almost certainly be the motor. 

 

M&L Premier, I believe.

 

5 minutes ago, J. S. Bach said:

You have heard bagpipes, haven't you?

 

An experience difficult to forget

[Ravenser]

So your Johnson Spinner is spinning?

 

This might be a weight distribution problem. But never having tangled with a Single I am not sure what should be done to fix it.

 

If it is nose- heavy , then the weight would go on the bogie and not the drivers. The traditional advice with 4-4-0s is to have the tender resting on the back of the cab to transfer weight onto the drivers. But here the axle closest to the tender is a trailing axle.

[Edwardian]

2 minutes ago, Ravenser said:

So your Johnson Spinner is spinning?

 

This might be a weight distribution problem. But never having tangled with a Single I am not sure what should be done to fix it.

 

If it is nose- heavy , then the weight would go on the bogie and not the drivers. The traditional advice with 4-4-0s is to have the tender resting on the back of the cab to transfer weight onto the drivers. But here the axle closest to the tender is a trailing axle.

 

No, it's more that my Achilles has a heel.

[Dava]

As a youth I put thin rubber bands round the driving wheels of my Caley Single for the same reason. Phenomenal adhesion but needed tender & preferably bogie pickup. This is an option, effectively traction tyres.

 

Other options:

Tender drive with weighted tender (granulated depleted uranium as coal if you can get it)

Drive the rear trailing axle as well as single axle (this was done on a Furness 2-2-2WT, requires clever gearing ratios).

 

Hope this helps.

 

Dava

[Ravenser]

1 minute ago, Edwardian said:

 

No, it's more that my Achilles has a heel.

I am not a builder of chassis for whitemetal kettles, but:

 

What if anything is supporting the front bogie? I can imagine that a Single is just as bad as a 4-4-0 for having all the weight forward on the bogie , and not much on the drivers.

 

On the "3 legged stool" principle, the two drivers would constitute two fixed points and the bogie pivot would constitute the third. The trailing axle would then need to "go along for the ride" - ie just float up and down and bear no weight, while the tender would lean on the back of the cab via the drawbar, applying weight to hold down the back.

 

I have no idea how such things could be contrived, least of all in a vintage whitemetal kit that has already been built. I know that one approach to getting the tender to hold the back down is the so-called "free bogie" tender . Here the back axle is fixed, the front end rides on the loco drawbar - and the front two axles form a loose sub-assembly and go along for the ride without carrying any weight - the "free bogie" of the name.

 

It is possible that with a rigid chassis the trailing axle is taking the weight rather than the drivers. If the front bogie is loose, and the drivers and trailing axle form a rigid 0-2-2 unit, with only 3 wheels actually touching , then those 3 wheels might be the 2 trailing wheels + 1 driver , not both drivers, plus a trailing wheel....

[Edwardian]

1 minute ago, Dava said:

As a youth I put thin rubber bands round the driving wheels of my Caley Single for the same reason. Phenomenal adhesion but needed tender & preferably bogie pickup. This is an option, effectively traction tyres.

 

The loco appears to have pick-ups one side only to the driver and trailing wheel. Nothing on the bogie or tender wheels, which strikes me as rather optimistic, but still.

 

1 minute ago, Dava said:

Other options:

Tender drive with weighted tender (granulated depleted uranium as coal if you can get it)

 

Would prefer to work with what I've got if I can

 

1 minute ago, Dava said:

Drive the rear trailing axle as well as single axle (this was done on a Furness 2-2-2WT, requires clever gearing ratios).

 

Probably the best way to do a single - make it a 4-2-2-0 - which is how the Rapido Stirling Single works.  Way beyond my  abilities, however. 

 

1 minute ago, Dava said:

Hope this helps.

 

Dava

 

Thanks

[Edwardian]

2 minutes ago, Ravenser said:

I am not a builder of chassis for whitemetal kettles, but:

 

What if anything is supporting the front bogie? I can imagine that a Single is just as bad as a 4-4-0 for having all the weight forward on the bogie , and not much on the drivers.

 

On the "3 legged stool" principle, the two drivers would constitute two fixed points and the bogie pivot would constitute the third. The trailing axle would then need to "go along for the ride" - ie just float up and down and bear no weight, while the tender would lean on the back of the cab via the drawbar, applying weight to hold down the back.

 

I have no idea how such things could be contrived, least of all in a vintage whitemetal kit that has already been built. I know that one approach to getting the tender to hold the back down is the so-called "free bogie" tender . Here the back axle is fixed, the front end rides on the loco drawbar - and the front two axles form a loose sub-assembly and go along for the ride without carrying any weight - the "free bogie" of the name.

 

It is possible that with a rigid chassis the trailing axle is taking the weight rather than the drivers. If the front bogie is loose, and the drivers and trailing axle form a rigid 0-2-2 unit, with only 3 wheels actually touching , then those 3 wheels might be the 2 trailing wheels + 1 driver , not both drivers, plus a trailing wheel....

 

I will have to look closely (but it's hard to concentrate with all that screaming), and, perhaps, take a video. 

[Michael Hodgson]

1 hour ago, Edwardian said:

Also, she makes a noise like a tortured cat (which I've never heard), or a child learning the violin (which I have).

 

I think you'll find violin strings are made from catgut, so the child cannot truthfully claim no animals were harmed

[J. S. Bach]

28 minutes ago, Michael Hodgson said:

I think you'll find violin strings are made from catgut, so the child cannot truthfully claim no animals were harmed

From Wikipedia:

"Catgut (also known as gut) is a type of cord[1] that is prepared from the natural fiber found in the walls of animal intestines.[2] Catgut makers usually use sheep or goat intestines, but occasionally use the intestines of cattle,[3] hogs, horses, mules, or donkeys.[4] Despite the name, catgut manufacturers do not use cat intestines."

 

https://en.wikipedia.org/wiki/Catgut

 

 

 

[Izzy]

Could the screaming perhaps be coming from the motor rather than the wheels slipping on the rail? Very subjective trying to describe sound like so much else, but I have heard motors scream through torque at differing speeds applied to their shafts. It might be a combination of a motor not powerful enough coupled with too low a gear ratio. So the motor wants to turn over faster than the wheel/axle revolution and thus helps cause the slippage. 

[Edwardian]

1 hour ago, Izzy said:

Could the screaming perhaps be coming from the motor rather than the wheels slipping on the rail? Very subjective trying to describe sound like so much else, but I have heard motors scream through torque at differing speeds applied to their shafts. It might be a combination of a motor not powerful enough coupled with too low a gear ratio. So the motor wants to turn over faster than the wheel/axle revolution and thus helps cause the slippage. 

 

Yes, I think the screaming may be the motor, so there is probably something else going on besides the slipping/or causing it?

 

It slips and screams, then stops and starts.  Turning the speed down a tad actually helps it to keep going/start again. Same phenomena in reverse, only more pronounced (and the screaming is louder).

 

What might these signs betoken?

 

 

EDIT: I know I could just give up, put it in a cabinet and listen to this instead ....

 

 

.... but even a noisy working engine is better than this and I need an excuse to finish my GWR Triang-bash clerestories. 

 

Help!!!

 

 

Edited February 2, 2021 by Edwardian

[Andy Hayter]

That rapid machine gun fire sound seems to me to be due to the motor worm and the gear wheel not being properly engaged.

[Edwardian]

Just now, Andy Hayter said:

That rapid machine gun fire sound seems to me to be due to the motor worm and the gear wheel not being properly engaged.

 

Yes. I tentatively suggested that things might not be meshing, so that makes sense to me. 

 

That means I need to find my screwdriver....!

[Edwardian]

Oh dear.

 

Upon taking the body off I found that the motor had been simply wedged into position by the body; the only thing that attached the motor to the chassis is the electrical connection. 

 

 

So, now I need to learn to mount the motor in such a way as the worm meshes with the gears but it still fits inside the body.

 

I had expected it to look more like this one ...

 

 

.... so am rather aghast. 

[Izzy]

Well, that at least explains it all. The motor lifting and gears de-meshing under load. Looks like one of the old Airfix/MRRC to me IIRC, or was it an early K’s? So long ago.

 

At least it’s solvable and could well run fine when done.

[Caley Jim]

12 hours ago, Edwardian said:

The loco appears to have pick-ups one side only to the driver and trailing wheel. Nothing on the bogie or tender wheels, which strikes me as rather optimistic, but still.

Could it possibly be the case that the wheels are insulated from the axles on one side, but live on the other so that it is picking up current from one side via the frames?  There only appear to be one lead to the motor, so is the other brush connected to the motor frame and via that to the chassis?  If so, then the motor jumping about would, as well as causing intermittent meshing of the worm/wormwheel (which is causing the noise), would result in an intermittent electrical connection.  The gears and bearings will also benefit from some lubrication.

 

I agree with the others that the adhesion issue is down to too much weight being carried by the bogie and carrying wheels.  I solved this on a 2-2-2WT I built by using beam compensation with the beam pivots as close as I could get to the driving axle to get the maximum weight on them.  Not an option on a ready built loco.

 

Jim

[Compound2632]

A motivational film. It's 33:45 - 34:22 you'll be wanting. 

 

https://player.bfi.org.uk/free/film/watch-the-brilliant-biograph-2020-online

 

Probably No. 3076 Princess Beatrice; just possibly Adelina Patti waving from the last carriage, which is almost certainly her private saloon, making this an up South Wales express.

 

[Devo63]

The motor appears to be an old K's Mark 1. These usually had a hole in each side plate tapped to 6BA which may line up with the middle hole in the chassis. If using a bolt to secure the motor to the chassis you must take great care to cut it to the right length so that it is firm in the motor frame but doesn't foul the armature. The worm and gear wheel do not seem to be from K's and look more like Romford offerings.

 

Dave R.  

[burgundy]

As Caley Jim has suggested, with a largely rigid frame, you have little control over the distribution of weight.

This thread was initially about a couple of singles and quite  a lot of effort went into getting the balance of the chassis more or less right. I am still building the layout that will demonstrate whether these locos have reasonable haulage power!

Best wishes 

Eric 

PS Fantastic film, Compound. Note in particular the proximity of the express before the track workers ambled out of the way!